Cellular communication system operable with transmission pathfault

Abstract

A communication system with fixed stations (FS), mobile stations (MS), and control stations (LS) is disclosed in which the control stations are interconnected by transmission paths and have additional, closed transmission paths connected to them. In the transmission paths, the fixed stations (FS) are arranged in series. Communication is on a time-division-multiplex basis. The control stations (LS) assign the TDM channels to the individual mobile stations (MS) via the fixed station (FS) in charge of the respective mobile station.

We claim: 
     
       1. A communications system including a plurality of control stations, a plurality of fixed stations and a plurality of mobile stations capable of communicating with selected ones of said plurality of fixed stations by radio, said communications systems being divided into cells each cell containing a control station and at least two fixed stations controlled by that control station, at least one of said plurality of control stations being colocated with an interface facility for providing connection of said at least one of said plurality of control stations to an automatic telephone network, and said plurality of control stations being interconnected by interconnecting transmission paths, the improvement in said communications system comprising: a plurality of closed transmission paths, each of said plurality of closed transmission paths being connected to an associated one of said plurality of control stations and each of said plurality of closed transmission paths beginning and ending at a predetermined one of said plurality of control stations associated therewith;   means for connecting each of said plurality of fixed stations to one of said transmission paths to enable each of said plurality of fixed stations to receive intelligence and control signals therefrom and to impart intelligence signals thereto, each of said transmission paths being bidirectional and having a predetermined number K of time-division multiplex channels provided for intelligence signals and a predetermined number L of separate time-division muitiplex channels provided for control signals in each direction;   means for assigning the control of fixed stations connected to said interconnecting transmission paths interconnecting at least first and second ones of said plurality of control stations in such manner that each of said first and second control stations controls communications from and to those fixed stations located on said interconnecting transmission paths nearest it, and for communication between one of said first and second control stations and the fixed stations controlled thereby and between another of said first and second control stations and the fixed stations controlled thereby, the occupation of said predetermined number K of channels begins at a first channel, while for direct communication between said first and second control stations the occupation of the K channels begins at channel K, and further channels are occupied in a continuous sequence, incrementally for said communications with said fixed stations, and decrementally for said direct control station communication.   
     
     
       2. A communications system including a plurality of control stations, a plurality of fixed stations and a plurality of mobile stations capable of communicating with selected ones of said plurality of fixed stations by radio, said communications systems being divided into cells each cell containing a control station and at least two fixed stations controlled by that control station, at least one of said plurality of control stations being colocated with an interface facility for providing connection of said at least one of said plurality of control stations to an automatic telephone network, and said plurality of control stations being interconnected by interconnecting transmission paths, the improvement in said communications system comprising: a plurality of closed transmission paths, each of said plurality of closed transmission paths being connected to an associated one of said plurality of control stations and each of said plurality of closed transmission paths beginning and ending at a predetermined one of said plurality of control stations associated therewith;   means for connecting each of said plurality of fixed stations to one of said transmission paths to enable each of said plurality of fixed stations to receive intelligence and control signals therefrom and to impart intelligence signals thereto, each of said transmission paths being bidirectional and having a predetermined number K of time-division multiplex channels provided for intelligence signals and a predetermined number L of separate time-division muitiplex channels provided for control signals in each direction;   means provided at each of said plurality of fixed stations for recognizing intelligence and control signals transmitted in either direction on a connected transmission path which are directed thereto and for further conveying intelligence and control signals not intended therefor in the same direction of transmission to neighboring ones of said plurality of fixed stations on said connected transmission path; and   means for assigning the control of communications from and to fixed stations connected to each of said plurality of closed transmission paths to first and second portions of said associated one of said plurality of control stations to which a given one of said closed transmission paths is connected, communication from and to fixed stations located nearest to said first portion of said associated control station being controlled from said first portion of said associated control station while communication from and to fixed stations located nearest to said second portion of said associated control station being controlled from said second portion of said associated control station.   
     
     
       3. The communications system according to claim 2 wherein each of said plurality of control stations having a closed transmission path connected thereto includes means for locating faults in said connected closed transmission path and means for opening said transmission path at fixed stations adjacent to a fault to cause information to be rerouted through said adjacent fixed stations to properly operating portions of said closed transmission path. 
     
     
       4. The communications system according to claim 2 wherein each of said plurality of fixed stations connected to a closed transmission path includes means for signaling a fault condition to said associated one of said plurality of control stations connected to that closed transmission path and means responsive to said associated control station to shift control of communications for that fixed station from one of said first and second portions of said control station to another of said first and second portions thereof. 
     
     
       5. The communications system according to claim 2 wherein said interconnecting transmission paths include an additional transmission path and upon an occurrence of a fault in a transmission path interconnecting control stations, intelligence and control signals to be exchanged between interconnected control stations are transmitted through portions of said interconnecting transmission paths not exhibiting said fault.